湖南不同母质植烟土壤钾的形态与特征

采集湖南烟区4种主要成土母质的16个具有典型代表性土壤样品,分析各形态钾的含量与比例。结果表明:紫色板页岩发育的土壤钾素库容量大,但有效钾含量相对较低,说明土壤对有效钾的保持能力有限;石灰岩发育的土壤矿物钾数量较少,但非交换性钾和有效钾的含量相对较高;第四纪红土发育的土壤在钾容量和自身补给潜力有限的情况下,维持了较高的有效钾水平,这可能与钾肥的施用及土壤对有效钾的保持有着密切的关系。不同母质发育土壤交换性钾只有27%是有效性较高的非特殊吸附钾,这可能直接限制了土壤短期钾的供应强度。土壤钾素有效性因成土母质的不同具有一定的差异,石灰岩发育土壤钾素有效性最高,其次为板页岩、第四纪红土,紫色板页岩最低。

Potassium form of soils from different parent materials in Hunan

The content and proportion of each form of potassium was analyzed from 16 representative soil samples derived from four soil parent materials in Hunan tobacco-growing areas. The results showed that the soil derived from purple slate parent ma-terial showed larger potassium storage capacity and lower available potassium content, indicating a limit ability to effectively maintain soil potassium; The soil derived from limestone parent material showed the smaller quantity of mineral potassium and a relatively higher content of non-exchangeable and available potassium. The limited potassium storage capacity and potential for self-compensation of soil available potassium and a high level of soil available potassium of soil from quaternary red clay parent material might have close relations with potassium application. There was only 27% non-specifically absorbed potassium that with high availability in exchangeable potassium content in soils developed from different parent materials which might directly limit the short-term soil potassium supply intensity level. The availability of potassium varied with parent materials, in order of limestone>board of shale>the quaternary clay>puple shale.